The present disclosure relates generally to the field of electrical current sensing devices. More particularly, the present disclosure relates to a micro-electromechanical system (MEMS) based current sensor using a force acting between current carrying conductors and a mutually inductive coupling.
Sensors for sensing a current based on the force between two current conductors are known in the art. It is known that a current carrying conductor produces a magnetic field in the vicinity of the current carrying conductor. It is also known that the magnetic field produced by the current carrying conductor can induce a force with another current carrying conductor disposed in the magnetic field produced by that current carrying conductor. While such known current sensors are capable of detecting currents in the “macro world”, they are not suitable for sensing currents in the nanotechnology scale environment of mechanical and electromechanical devices produced by micromachining processes.
Additionally, such known current sensors have several disadvantages. In general, the physical and electrical operating characteristics of such known current sensors are not compatible with sensing currents in the nanotechnology scale environment. The physical dimensions of these current sensors are one barrier. The electrical operating characteristics also prove disadvantageous in that a magnetic field produced by a current carrying conductor and sensed by the macro-sized current sensor tends to vary across the area of the sensor. This introduces an error that must be compensated for in order to achieve accurate current measurements. Also, known current sensors are individually fabricated and packaged devices dedicated to performing a single function in the process of current sensing. Each of these attributes adds cost and application limitations of the current sensor. Further, the macro-sized current sensors tend to produce heat, thereby reducing the efficiency of the current sensors and introducing a possible error factor to the accuracy of the current sensor.
Thus, there exists a need in the art for a MEMS-based current sensor using the force between current carrying conductors and a mutually inductive coupling that overcomes one or more of the aforementioned deficiencies of known current sensors using the force between current carrying conductors.